CREW Guidelines for Weeding

M Misleading (and/or factually inaccurate)
U Ugly (worn and beyond good mending/rebinding)
S Superceded (by a truly new edition or by a better book on the subject)
T Trivial (of no discernible literary/scientific merit)
I Irrelevant to the needs/interests of community
E Elsewhere available expeditiously

3-part Formulas for Crew weeding:

8/3/MUSTIE=

Consider a book in this category for discard when latest copyright is more than 8 years old.

Consider a book in this category for discard when last circulation/inhouse use was more than 3 years ago.

Age category varies considerably by subject